midi keyboard recommendation

Dear 64studio folks, Hello after a long time. I am now running the 3.0 beta version of 64 studio on an AMD 64 box installed on a SATA drive. I've got an M Audio delta 1010. I haven't installed the sound card for it and played around with it yet. I also have a Seck 12 8 2 desk that I now have an instruction manual for. I've been incredibly busy starting a scientific business. I printed out the Audio installation write up. I am trying the very first item on it which is called getting started with LinuxSampler by Kevin Donnelly. I am currently downloading the Maestro Concert Grand Sampler from the linuxsampler.org web site. This seems to be working. But I notice from reading Mr Donnelly's guide that I need to attach what I assume is a musical keyboard to the computer. I googled this a little and it seems like I could probably buy one that has a USB port on it as well as an ordinary MIDI output of some kind. I assume at a dumb level that if I went out and bought one that had a USB port on then an ordinary bog USB cable ought to be able to connect it to the PC and then it would drive Rosegarden or whatever Mr Donnelly is recommending it to then be able to do........ What make or model of a simple MIDI keyboard would do for the likes of me? Could I get one from somewhere ordinary like PCWorld? Are they expensive things? There is another topic on this forum about inexpensive keyboards but I don't think it actually recommended which ones to go out and buy. I also have a Roland GR1 guitar synthesiser with a conventional MIDI output. I guess in theory it could be used to drive Rosegarden or whatever and then play this concert grand sampled piano and make a recording which I think is what you are meant to do in this particular exercise. Suggestions on selecting a keyboard. If I succeed with this activity, the next section is about mastering apparently. I think it could take me a while to wade through the whole 46 pages and learn to do everything before I finally get to point where I will connect up the M Audio device and then have a go at recording live sounds through the mixer. I need to go through your previous recommendations made on line here to test out the mixer itself before doing this. What sort of monitor speakers would you recommend I get to attach to the computer here? I have some cheap tatty ones but I think I need proper ones really.... Regards Michael Fothergill